1. Department of Medicine, School of Medicine, Pusan National University, Yangsan, Korea.
2. Department of Preventive, and Occupational & Environmental Medicine, School of Medicine, Pusan National University, Yangsan, Korea.
3. Environmental Health Center of Asbestos, Pusan National University Yangsan Hospital, Yangsan, Korea.
4. Department of Occupational and Environmental Medicine, Pusan National University Yangsan Hospital, Yangsan, Korea.